Device for testing video signals



FIG. 1 is a perspective view of a device for testing video signals, said perspective view showing a front view, a left side view and a top view thereof.

FIG. 2 is a left side elevational view thereof, wherein a right side view is a mirror image of the left side view; and,

FIG. 3 is a front elevational view thereof.

The appearance of a bottom and a back forms no part of the claimed design. 

The ornamental design for a device for testing video signals, as shown and described. 